Spark-plug



UNITED STATES PATENT OFFICE.

WALLAGE W. BUGH, OE NORTH TONAWANDA, NEW YORK.

SPARK-PLUG.

Speciflcation of Letters Patent. Pateted Septi 16, 1919.

Application filed October 9, 1918. Serial No. 251494.

To all whom 'it may concem:

Be it known that I, WALLACE W. BUGH, a citizen 'of the United States, residing at North Tonawanda, in the County of Niagara and State of New York, have invented new and useful Improvements in Spark-Plugs, of which the following is a specification.

This invention relates to spark plugs especially designed for use in connection with internal combustion engines.

One object of the present invention is the provision of a spark plug in which 'the coupling is fastened on the core in such manner as to render the union airtight.

Another object of the invention is the pro- Vision in a spark plug, of means, preferably resilient, for holding a shoulder on an electrode in airtight engagement with a comple-' mentary abutment of the core to afford an airtight engagement independent of expan'- sion or contraction of the electrode.

Another object of the invention is to produce a spark. plug which is practically airtight and leak-proof and which can not be tampered with by the owner of the plug but which at the' same time may be readily eleaned as far as the 'power and ground electrodes or sparking points are concerned. One of the great disadvantages of the ordinary spark plugs now in common use is that it consists of a number of parts which may be easily separated from each other by the average owner of a motor vehicle, with the result that the parts are not properly reassembled by such person not skilled in the art, the result being an inoperative or at the best an ineflicient and unsatisfactory plu The present invention overcomes that di culty approximated by the Construction herein shown and described. i

With the above and other objects in View, the invention consists' in the novel construction,` combination and arrangement of parts herein fully described, illustrated and claimed.

Figure 1 of the accompanying drawings represents a central longitudinal section through the improved spark plug.

Fig. 2 is a similar view showing the spark plug ina modified form. 4

The' present invention relates mainly to the core and the attachment thereof't-ogether i with the central or power electrode, as an inclosing metallio shell and ground electrode of any approved formation may be employed in connection with the structure illustrated in Figs. 1 and 2 of the accompanying drawing.

Referring to the drawings 1 designates the coreof a spark plug, said core being ordinarily formed of porcelain, or other appropriate insulating material. 2 designates the power electrode which passes centrally and longitudinally through the 'core 1, the bore 3 in the core being of just suflicient size to admit of the insertion of the power electrode therethrough and the inner extremity of the bore 3 being flared or enlarged in conical formation as shown at 4. The power electrode 3 is formed with an enlargenent or collar 5 having a cone-shaped face 6 which is adapted to fit snugly and tightly against the flared or cone face 4 of the core 1. A tight joint is thusformed between the power electrode and the inner end of the core. The core is provided with the usual enlargement or circumferential flange 7 adapting it to be firmly and positively .outer end` thereof with an enlarged head or collar 8 which forms an integral part of the core and forms a part of the means by which the catch hereinafter 'referred to is fastened to the core.

In connection with the outer end of the core 1, I employ a metal cap 9 of cylindrical or disk formation having its peripheral edge threaded to be engaged by an internally threaded' union or coupling member 11 which surrounds the flange or head 8 and has its inner edge swaged to form an inwardly extending annular lip 12 which underlies and bears firmly against the inner surface of the head 8. An air-tight gasket 13 preferably of some hard compressible material is interposed between the cap 9 and the outer end of the core 1 being held under compression by the inwardly swaged annular lip` 12, thus forming a leak-proof air-tight joint at this point.

Extending upwardly from the cap 9 is a sleeve-like extension or elongated cooling sleeVe 14 which also surrounds the power electrode 2 as shown in Fig. 1. A part of the sleeve-like extension 14: is enlarged as shown at 15 and such enlarged portion is formed with an annular groove or seat 16 designed to receive the terminal of the ignition feed wire used in conjunction with the plug. The extreme outer end of the sleeve-like extension 14 is enlarged as shown' .e m me to form e hollow charnber 18 in which is :irranged e coled compression spring 19 which surrounds 'the enter end portion of theelectrode 2, hearing &tone end against the inner wall 20 of the chamber 18 and hearing at .its outer end against a coller or shoulder 21 on the electrode 2. The spring 19 operates to hold the extremities 5 and 6 in air-tight contact with each other.

By means of the construction hereinebove described and shown in Fig. 1, zt fixed airtight and leak-proof connection is estab- -lished between the power electrode and the core and also between said 'electrode and the cep to which the terminal of the circuit wire is attached. The parts can not be separated,

thereby rendering the plug leak-proof and,

adapted :tor long efiicient service.

If desirecl the plug as a whole may be made relatvely shorter by resorting to the Construction and arrangernent illustreted in Fig. 2, in which the cep indicated at 9' is formed with an internal chamber 22 to re- 4 ceiVe the spring' 19' which holds the shoulders of the core 1 and the electrode 2 in firm engagement with each other. The union or coupling 11( secures'the cap 9' to the core 1 in the same'manner as described in con nection with Fig. '1, and also serves to compress the gasket 13' which is interposed between said cap 9' and the adjacent end of the core 1." The cep 9' is formed with a socket 23 in the 'end thereof to receive the terminal of'the circuit or current wire which 4 ont" said core and having e bevelecl shoulder whiclrpresses against a corresponding beveled shoulder at the inner end of seid core, e cep at the outer end of seid core, a nnion connecting said cap and core, and zt spring engaging seid electrode and cep and serving to maintain air-tight contact between the shoulders of the core and electrode, seid cap being formed with an air-tight chamber inclosing said spring.

2. In e spa'k plug the combination of a core, a power electrode extending longitndi-` nally therethrough, contacting air-tight shoulders on said electrode and core, a spring for holding said shoulders in engagement with each other, a cep inclosing said spring and a, portion of said electrode, a, union connecting said cep and core, and an eir-tight gasket interposed between said cap and core.

3. A sperk plug from which air is ex-.

cluded comprisng a core, an electrode eX- posed at the inner end of the core, and a cep fastened in air-tight manner on the outer portion of the core and entirely inclosing the electrode and having an elongated cooling sleeve closed at its outer end.

4. The combinetion in a spark plug, of e core, an electrode extending longitudinally therethrough, portions .on said core and electrode afi'ording an airtight joint, resilient means for holding said portions in engage: ment, and a cep inclosing said resilient means and connected in airtight manner with the core.-

5. In a spari( plug, the combination of a core, an electrode extending longitudinally therethrough, Contacting airtight shoulders on said core and electrode, a cap connected to the core, an elongated cooling sleeve on said cap, and a spring for holding said shoulders in' engagement with each other, said cep and sleeve forming an inclosure for the spring and a portion of the electrode.

In testimony whereof I afix my signature.

WLLACE w. BUGH. 

